1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
#
# Copyright (C) 2008, 2009 Wayne Meissner
# Copyright (c) 2007, 2008 Evan Phoenix
# All rights reserved.
#
# This file is part of ruby-ffi.
#
# This code is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License version 3 only, as
# published by the Free Software Foundation.
#
# This code is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
# version 3 for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# version 3 along with this work. If not, see <http://www.gnu.org/licenses/>.
#
require 'ffi/platform'
module FFI
class Pointer
# Pointer size
SIZE = Platform::ADDRESS_SIZE / 8
# Return the size of a pointer on the current platform, in bytes
# @return [Numeric]
def self.size
SIZE
end
# @param [nil,Numeric] len length of string to return
# @return [String]
# Read pointer's contents as a string, or the first +len+ bytes of the
# equivalent string if +len+ is not +nil+.
def read_string(len=nil)
if len
get_bytes(0, len)
else
get_string(0)
end
end
# @param [Numeric] len length of string to return
# @return [String]
# Read the first +len+ bytes of pointer's contents as a string.
#
# Same as:
# ptr.read_string(len) # with len not nil
def read_string_length(len)
get_bytes(0, len)
end
# @return [String]
# Read pointer's contents as a string.
#
# Same as:
# ptr.read_string # with no len
def read_string_to_null
get_string(0)
end
# @param [String] str string to write
# @param [Numeric] len length of string to return
# @return [self]
# Write +len+ first bytes of +str+ in pointer's contents.
#
# Same as:
# ptr.write_string(str, len) # with len not nil
def write_string_length(str, len)
put_bytes(0, str, 0, len)
end
# @param [String] str string to write
# @param [Numeric] len length of string to return
# @return [self]
# Write +str+ in pointer's contents, or first +len+ bytes if
# +len+ is not +nil+.
def write_string(str, len=nil)
len = str.bytesize unless len
# Write the string data without NUL termination
put_bytes(0, str, 0, len)
end
# @param [Type] type type of data to read from pointer's contents
# @param [Symbol] reader method to send to +self+ to read +type+
# @param [Numeric] length
# @return [Array]
# Read an array of +type+ of length +length+.
# @example
# ptr.write_array_of_type(TYPE_UINT8, :get_uint8, 4) # -> [1, 2, 3, 4]
def read_array_of_type(type, reader, length)
ary = []
size = FFI.type_size(type)
tmp = self
length.times { |j|
ary << tmp.send(reader)
tmp += size unless j == length-1 # avoid OOB
}
ary
end
# @param [Type] type type of data to write to pointer's contents
# @param [Symbol] writer method to send to +self+ to write +type+
# @param [Array] ary
# @return [self]
# Write +ary+ in pointer's contents as +type+.
# @example
# ptr.write_array_of_type(TYPE_UINT8, :put_uint8, [1, 2, 3 ,4])
def write_array_of_type(type, writer, ary)
size = FFI.type_size(type)
tmp = self
ary.each_with_index {|i, j|
tmp.send(writer, i)
tmp += size unless j == ary.length-1 # avoid OOB
}
self
end
end
end
|
